2 Volt Accumulator.

[emeritus]

A simple way to limit current us to use a tungsten filament lamp in series. I have accumulated a number of 12V car bulbs for this use. A 12V 21W used with a 5A max 12V trickle charger charger and a 12V battery will limit to about 1.5A, and the non-linear temperature coefficient of tungsten provides a rough approximation to a constant current load. Many traditional car bulbs use the single contact SCC base and I have a range from 5W to 36W. SCC lampholders are uncommon, but the CPC catalogue I have just receive now has them (and SBC lampholders) as a new products and they are quite cheap.

[HamishBoxer]

EDTA is what is used for cleaning ones arteries.

[Cobaltblue]

I have a couple of new and boxed Radio accumulators (Exide) and a couple unused WD types. I considered filling them 3 decades ago but I keep them as they are rare surviving examples. I can easily hide a Cyclon in a used example and have done so. When used ones turn up which is less and less often now they are dry with the remainders of the plates in a mess at the bottom of the glass case.
The celluloid ones are even worse with the case brittle and split.

It you talk to anyone who lived in a rural area during the 30's through to the 50's they will all tell you tales of getting the Battery charged every week often at a cycle shop or a garage rather than the local Radio shop. Certainly it's a story my parents Mother Kelynack Moor (st Just) and my father Gwavas (Newlyn) have told me many times. Neither remember the radios so powered.

The upkeep of their accumulators (most people had 2 one in use one on charge). was woven into the lives of those who had battery Radios. I think some people only rented their accumulators.

Cheers

Mike T

[mole42uk]

Originally Posted by NottsIan

I've read somewhere that EDTA is not soluble in sulphuric acid so the revivers don't work well. If the acid is drained out and the cell flushed with distilled water a solution of EDTA can help remove sulphation after which the cell should be refilled with fresh acid and slowly charged. I've not yet had the opportunity to test this myself.

I did exactly that several years ago. I used to live off-grid and bought a lot of glass-cased 2V lead-acid accumulators from a defunct PO telephone exchange. Those that had intact glass cases still contained acid and the plates were in a bit of a state with layers of shedded material on the bottom. I emptied them all, cleaned thoroughtly with spring water, some I even melted the pitch sealing to remove the plates for thorough cleaning. They were all treated with EDTA, rinsed and filled with acid solution.

Although some did not survive, I still managed to recover enough to make the required 48V battery to power my inverter. Those cells lasted for a few years until I was fortunate to obtain some much more modern stand-by cells....

[EF80TVVALVE]

I've heard a few stories of people having the weekend job of exchanging the accumulators, often in the carrying cradle swinging from their bicycle handle bars! They were obviously very common, I have a few friends who are into 'dump digging' and they quite often pull out these batteries in 30s-40s tips, which is actually where this one came from. I have another Exide type DFG but the plates are much more worn, although it does still have around 3/4 of the active material left on the positive plate. This one is missing the filler vent cap, so if I find one that fits I may well see if this one has any life in it too.

I remember using Granville Bat-Aid tablets in a car battery some years ago, they didn't do anything to improve it and withing two weeks the battery gave up completely! I resumed from then that they probably don't work for a majority of batteries, maybe they help at early stages of sulfation

[Bazz4CQJ]

EDTA is what's known as a chelating agent https://en.wikipedia.org/wiki/Ethyle...ating%20agent.. Potentially, it helps to dissolve compounds which are otherwise quite insoluble, by converting them in to EDTA complexes which are soluble. Citric acid is a chelating agent. So lead sulphate goes to lead EDTA complex.

I've never used EDTA on a battery, but I'd imagine it would take some time (several hours or even a day or two) to work, but if anyone has reliable info, that would interesting. Currently, I'm using my pulsator on a 5Ah SLA which powers my old (pre Li-ion) lawn edge trimmer. The 3-year old battery seems down on power; I normally get ~5 years from them.

As I said earlier, the pulsator will only act on sulphated batteries and so too EDTA (potentially), but sulphation is not the only failure mode of LA batteries.

B

[emeritus]

My 1940's book doesn't have anything much good to say about contemporary battery remedy additives other than being something to try as a very last resort when all else had failed, but implied that the chance of sucess was not good.

At my school in the 1960's we used to use similar 2V accumulators in the physics lab for experiments requiring a stable DC voltage such as measuring resistance with a Wheatstone bridge. I think they must have been larger han the ones found in radios, but I have never seen a radio accumulator in the flesh, only photos and line drawings .

[Bazz4CQJ]

Originally Posted by emeritus

My 1940's book doesn't have anything much good to say about contemporary battery remedy additives other than being something to try as a very last resort when all else had failed, but implied that the chance of sucess was not good.

I think the term "Snake Oil" is hanging in the air, but I could be wrong.

B

[Herald1360]

Presumably if you get rid of enough lead sulphate, there won't be enough left to convert to spongy lead and lead oxide when charging the accumulator to provide useful capacity. It's not the presence of the lead sulphate that's the problem but the physical state of what there is.....

[MotorBikeLes]

EDTA, ethylene di-amine tetra acetic acid as I recall. 55 years ago I was using it in qualitative analysis for lime and magnesia. It was known as an adsorbtion indicator, as there was a colour change took place on the insoluble component.
With regard to your missing plug, I think I have an Exide screw type plug from an old car or M/C battery, so a photo of the top could be helpful.
Les.

[EF80TVVALVE]

Hi Les,

I've managed to find a photo of the cap used on these exide batteries. I don't know if they were similar as their car batteries or not but hopefully it will help identify whether it is an identical type.

[MotorBikeLes]

EF80+, I recognize that from long ago, but sorry, not the same as the ones I have, which are white, plastic or porcelain (I forget) and somewhat taller. I am fairly certain they are from a M/C battery that I gutted for its case, as it was well too far gone 30 years before I had it.
Cheers, Les.

[HamishBoxer]

A late reply to EF80,I will indeed leave my nos accumulator as it is.Not stuck for a 2 V supply.